One exemplary standard discussed herein is the Precision Time Protocol (PTP), described by IEEE 1588-1008, which is a standard for synchronizing real-time clocks for communication among nodes of a distributed network. Such protocols enable accurate and precise synchronization of clocks in measurement and control systems using technologies such as network communication, local computing, and distributed objects. IEEE 1588 is a protocol for providing synchronization through exchange of packets over a network. The objective of hardware implement is high precision. Designing hardware that implements entire IEEE 1588 is rather complex.
The PTP is applicable to systems communicating by local area networks supporting multicast messaging, including Ethernet computer networking technologies. The PTP is designed for local area networks requiring accuracies beyond those attainable by a Network Time Protocol (NTP), which achieves accuracies of only one millisecond to tens of milliseconds.
IEEE 1588-1008 enables heterogeneous systems that include clocks of various inherent precisions, resolutions, and stabilities to synchronize to a master clock. IEEE 1588-1008 also supports system-wide synchronization accuracy in the sub-microsecond range with minimal network and local clock computing resources. IEEE 1588-1008 is appropriate for applications that cannot bear the cost of a GPS receiver at each synchronized node, or for which GPS signals are not accessible.
Measurement and control applications, requiring accurate timing and synchronization, increasingly employ distributed technologies such as network communication, local computing, and distributed objects. Many of these applications are enhanced by having an accurate and precise system-wide measurement of time achieved by having distributed local clocks in each sensor, actuator, or other system device. The improvement of the accuracy and the granularity (smallest visible time duration) of precision of these distributed local clocks in such systems is an active area of research.